It has heretofore been proposed, in U.S. Pat. No. 2,138,887 to Segal of Dec. 6, 1938, to mount an odometer within one of the forward wheels of a roller skate, the odometer window being in the outer disc shaped retaining plate of the forward wheel and thus difficult for the skater to view while wearing the skates.
In U.S. Pat. No. 2,354,708 of Aug. 1, 1944, also to Segal, the measuring wheel, or odometer, is also mounted within the roller skate wheel and includes a needle, or pointer and dial readable on the outer side of the skate, but difficult for the skater to read, while wearing the skate, because the human leg does not bend easily sidewise outwardly.
A rolling hoop toy is provided with an odometer in U.S. Pat. No. 3,387,778 to Althaus of June 11, 1968 the odometer, or counting register, also being mounted diametrically across the span of the central opening of the circular hoop, and the viewing window being within the hoop and difficult to view.